Beaver Dams and Their Effects on Urban Streams in the Tualatin River Basin, Northwestern Oregon

Fact Sheet 2025-3022
By: , and 

Links

Introduction 

In response to growing interest in beaver-assisted restoration in the Tualatin River Basin of northwestern Oregon, the U.S. Geological Survey (USGS), in partnership with Clean Water Services, collected data from 2016–17 and completed a series of studies to: (1) inventory known locations of beaver dams and activity in the Tualatin River Basin, (2) estimate the number of beaver dams in the Tualatin River Basin as of 2017 and the potential number of beaver dams that could be supported with riparian vegetation improvements, and (3) assess the effects of beaver dams and ponds on storm hydrology, hydraulics, and floodplain inundation, suspended-sediment transport and deposition, and water quality along two urban stream reaches (Fanno Creek at Greenway Park and Bronson Creek between Kaiser and Saltzman Roads). This fact sheet summarizes the results of these studies and implications for beaver-assisted restoration in the Tualatin River Basin.

Suggested Citation

Jones, K.L., Smith, C.D., White, J.S., Rounds, S.A., Doyle, M.C., and Leahy, E.K., Beaver dams and their effects on urban streams in the Tualatin River Basin, northwestern Oregon: U.S. Geological Survey Fact Sheet 2025–3022, 6 p., https://doi.org/10.3133/fs20253022

ISSN: 2327-6932 (online)

Study Area

Table of Contents

  • Key Findings and Implications for the Tualatin River Basin
  • Introduction
  • Abundance and Distribution of Beaver Dams in the Tualatin River Basin
  • Estimates of the Number of Current and Potential Beaver Dams
  • Effects on Water Movement and Floodplain Inundation
  • Effects on Suspended-Sediment Transport and Deposition
  • Effects on Summer Water Temperature
  • Water-Quality Variability in a Beaver Pond
  • Implications for Management and Habitat Restoration
  • Examples of Benefits and Challenges Associated with Beaver Dams and Ponds
  • Full Results of the Study
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Beaver dams and their effects on urban streams in the Tualatin River Basin, northwestern Oregon
Series title Fact Sheet
Series number 2025-3022
DOI 10.3133/fs20253022
Publication Date September 30, 2025
Year Published 2025
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Oregon Water Science Center
Description 6 p.
Country United States
State Oregon
Other Geospatial Tualatin River Basin
Online Only (Y/N) Y
Additional publication details